New York University professor Paul Light, who has studied the executive branch for decades, thinks much of the blame goes to Congress and what he calls a "Napoleonic approach to defeating the president and reducing big government."

Light argues that those who oppose new laws are required by the Constitution to repeal them. But he says that has all changed recently.

"If you don't like a law now, and you can't repeal it," Paul says, opponents work to "decapitate the agency and eviscerate its capacity to execute the law."

Lack of leadership can leave some federal agencies treading water on policy and personnel issues. Sometimes key decisions get put off. And if the president doesn't have his choices in place, it's a lost opportunity to effect policy.

Among the agencies operating without permanent leadership:

-- The Bureau of Alcohol, Tobacco, Firearms and Explosives, which has not had a permanent administrator since 2006, the year Congress required that the director be confirmed by the Senate.

-- The Centers for Medicare & Medicaid Services, which oversees those massive health care programs and hasn't had a director confirmed by the Senate in seven years. NPR's Julie Rovner tells Morning Edition that the agency also handles the Children's Health Insurance Program and now "a big chunk of the Affordable Care Act." She says in 2011, it handled about 21 percent of the federal budget, or $769 billion.

-- The Consumer Financial Protection Bureau. President Obama named Richard Cordray director in a recess appointment in 2011, which is now being challenged in federal court. Cordray has been re-nominated by the president, and his confirmation hearing is set for Tuesday.

-- The Federal Election Commission, which has commissioners held over on expired terms.

NPR's Carrie Johnson says of the nearly 90 federal judgeships currently vacant, about 30 are considered judicial emergencies. "That means the caseloads in those courts are very, very high. And the impact is that judges who are currently on the bench are hearing lots more cases."

While Senate Republicans are responsible for most of the roadblocks before the president's nominees now, Democrats have pulled similar moves when it was a Republican president doing the nominating.

Sometimes, the roadblocks aren't about philosophy or even politics, but rather a senator's effort to win something for his or her state. For instance, Alaska Republican Sen. Lisa Murkowski is threatening to block Obama's nominee to lead the Interior Department, Sally Jewell, over construction of a road through a wilderness area that the department opposes.

But those sorts of roadblocks, used as leverage for something a lawmaker wants for her state are relatively rare nowadays, according to NYU's Light.

"I don't see as much of that going on," Light says. "I don't see a lot of hostage-taking based on personal demands and favors. I see a lot related to just plain anger toward the president, and a reluctance to see the laws fully and faithfully executed."

It's important to note that the vacancies at the top of these agencies have nothing to do with the sequester, which is forcing many federal departments to trim back their spending levels.

It's not solely Senate Republicans who are to blame for the headless government. Obama has failed to put forward nominees for some posts, and Light says the president is "moving at a snail's pace" to make other nominations.

Light says the administration also has "the longest questionnaire in the presidential history for vetting people who might become nominees. It's brutal." That serves to discourage some people from wanting to become nominees in the first place.

Some workers dream about having no boss. Thousands of federal workers are living that dream. Many federal agencies, commissions and courts are operating without permanent leadership. Sometimes, the White House has been slow to nominate anyone. Often, the Senate has not confirmed President Obama's nominees.

New York University's Paul Light says Republican senators have strategic reasons to confirm nominees very slowly.

PAUL LIGHT: It's a Napoleonic approach to defeating the president and reducing big government. I mean if you don't like the law, the Constitution is quite explicit. You're obligated to repeal the law. But in recent decades that has all changed. If you don't like a law now, and you can't repeal it, decapitate the agency and eviscerate its capacity to execute the law.

INSKEEP: For example, keep it from having any administration-appointed senior officials. Just to be clear, this has nothing to do with automatic spending cuts or any of the other budget battles in Washington. It's a story of hiring, or not hiring, key members of an administration.

We're going to talk about the effects with a group of NPR correspondents, starting with NPR's Brian Naylor.

Brian, good morning.

BRIAN NAYLOR, BYLINE: Good morning, Steve.

INSKEEP: How many agencies, commissions, courts are we talking about here?

NAYLOR: Well, according to one count from the folks at ProPublica, there are 68 vacant positions at the end of the president's first term, which is more than the previous two administrations.

INSKEEP: And we're not just talking about 68 jobs - this is 68 top jobs here.

NAYLOR: These are top jobs. There's a key Medicare agency that hasn't had a permanent director since 2006; the Federal Election Commission, which has had commissioners held over on expired terms. There's the National Labor Relations Board, which President Obama filled with some recess appointments, but those were deemed unconstitutional by a federal appeals court - though they still remain in office. There are also plenty of lower-level vacancies that the administration hasn't gotten around to filling so far, but those have less of an impact.

INSKEEP: OK. So elections, the workplace, Medicare, Medicaid - these are agencies that have something to say about huge swaths of American life. What is the effect of them not having heads?

NAYLOR: Well, you know, just imagine. I mean, they're treading water on policy and personnel issues. Sometimes, key decisions get put off and frankly, lost opportunity. If you're the president and you don't have your folks in place, it's a lost opportunity to affect policy.

INSKEEP: All right. You mentioned a Medicare agency. Let's bring in NPR's Julie Rovner, who covers health policy. Julie, what is that agency, and what's the effect here?

JULIE ROVNER, BYLINE: It's the Centers for Medicare and Medicaid Services. It's actually a lot bigger than that. It handles not only Medicare and Medicaid, but the Children's Heath Insurance Program and now, a big chunk of the Affordable Care Act. Together in 2011, it handled about 21 percent of the budget, $769 billion - that was bigger, by some accounts, than the Defense Department. And as you mentioned, there has not been a Senate-confirmed head since 2006. So that dates back to the Bush administration.

INSKEEP: So we hear about the defense secretary. We just had a confirmation battle over the defense secretary. This is somebody whose job, in dollar terms, is perhaps bigger.

ROVNER: That is correct. And...

INSKEEP: Who is it right now?

ROVNER: It is - right now, there is an acting administrator, Marilyn Tabner; she's been acting for about a year. Before that there had been another acting administrator, Don Berwick, who is respected by just about every health authority in the United States, apparently, except the United States Senate, who refused to confirm him. Before that, the Democrats refused to confirm the last Bush appointee. And now, of course, it became a huge conflagration over the Affordable Care Act; that's why the Republicans said they would filibuster first Don Berwick and now, they're not so sure about Marilyn Tabner. So again, there's simply been an acting director of this agency.

INSKEEP: OK. Let me bring in NPR's Yuki Noguchi, who covers financial matters - because there's a special battle over the head of a particular agency, the Consumer Financial Protection Bureau, which you cover.

YUKI NOGUCHI, BYLINE: Yeah. That has a director, Richard Cordray, who was appointed through a recess appointment, which is now being disputed. And the Republicans in the Senate are angry about that appointment not because they have objections to Cordray himself, but because they don't like the structure of the Consumer Financial Protection Bureau. They say it has too much power.

INSKEEP: They don't like what the agency is doing or set up to do.

NOGUCHI: Well, they want to have the final say-so on what the bureau writes in terms of rules.

INSKEEP: And this is why the president, unable to get his nominee through the Senate, effectively did it himself, and now this is a matter for the courts?

NOGUCHI: It is a matter for the courts to decide. And then also he's been re-nominated so there will be a hearing next week.

INSKEEP: OK. So we have that situation. We have the Medicare situation. There's even more. I'd like to know from you, Brian Naylor, who's still with us - are these delays normal? Is this the normal way of doing business in Washington?

NAYLOR: Well, it's sort of become the new normal. It used to be that senators would hold nominations because they wanted to extract something - some personal favor from the administration. But that is pretty rare, those sorts of personal holds. Right now it's more of an institutional, we-won't-even-bring-this-up-for-a-vote kind of thing.

INSKEEP: It's a power grab. That might be a rude term for it. But that's what you're saying - the Senate is asserting more power than they've had in the past.

NAYLOR: That's right.

INSKEEP: OK. Let's discuss the courts. And NPR's justice correspondent, Carrie Johnson, covers that area. What does it mean to not have scores of federal judges filling particular spots on the bench?

CARRIE JOHNSON, BYLINE: Steve, nearly 90 judgeships are vacant. About 30 of those are considered judicial emergencies. That means the caseloads in those courts are very, very high. And the impact is that judges who are currently on the bench are hearing lots more cases. And there's a huge impact too on senior or retired judges, judges who agree to hear a few cases now and then...

INSKEEP: They un-retire now...

JOHNSON: Well, many of them are hearing a full caseload and some of them are even doing what's called circuit riding, which back in the day meant riding your horse to another location and hearing cases in that location to help that court out. A lot of senior judges are doing that. One from Washington, D.C. recently went to Atlanta to help out with that court's caseload. That's happening more and more.

INSKEEP: And the cost of horse feed, I imagine, is going through the roof here.

JOHNSON: Or at least airline tickets.

INSKEEP: Airline tickets - what it would be today. There is the old saying that justice delayed is justice denied. Is justice being delayed for a lot of criminal defendants here?

JOHNSON: What happens in these cases is that criminal matters get priority. So the delays are mostly happening on the civil side. However, that can have a huge impact on the lives of ordinary people. People contesting or challenging a denial of Social Security benefits, people who have personal injury lawsuits, and many people who are challenging denial of, say, their military benefits - all of those people have righteous disputes and they need them heard quickly.

INSKEEP: Let me come back to Brian Naylor here, because Brian, at the beginning we had a political scientist who said this was a Republican strategy, a Napoleonic effort to take down the administration. Is that - if you talk to Republicans in the Senate, would they admit that's what they're doing?

NAYLOR: I think they might in some of their more honest moments, or off the record. But some of the blame has to fall on the administration itself, the Obama administration, previous administrations, for not aggressively pursuing some of these nominations, for letting some of these vacancies just remain vacant. And there's also an incredibly intrusive process to become a nominee. They want to know a lot about your background, a lot about your finances. And for some nominees, I think it makes it more difficult for the administration to get nominees for some of these positions. People say it's just not worth it.

INSKEEP: That's NPR's Brian Naylor along with NPR's Julie Rovner, Yuki Noguchi and Carrie Johnson, telling us about headless government agencies. Thanks to you all.

JOHNSON: Thank you.

ROVNER: Thanks, Steve.

INSKEEP: Another Democratic president has evolved on gay marriage. Bill Clinton says he now opposes the Defense of Marriage Act. Clinton was considered supportive of gay rights in the 1990s, though the end result was often messy and much-debated compromises, like the military's "don't ask, don't tell" policy, which has since been repealed. When President Clinton signed the Defense of Marriage Act in 1996, it prevented the federal government from recognizing gay marriages in any way. Now the former president has written an article for the Washington Post. He says he only signed the Defense of Marriage Act in order to head off a movement for even stronger measures. And he says he has come to the conclusion that the Defense of Marriage Act is, quote, "incompatible with our constitution." Two weeks ago, the Obama administration also took an official stand against that law, calling it a harsh form of discrimination. And later this month, the Supreme Court hears arguments in a case that challenges the law. Transcript provided by NPR, Copyright NPR.